It generally is not recommended to consume any foods, including dairy, beyond the use by date. This is because the growth of bacteria in the products, which cause spoiling, can increase to a level which may impact on one’s health.
Best before dates on food is different and where the degradation of the food through storage results in loss of nutritional value or food quality.
Food Standards Australia has information on use by and best before dates…
https://www.foodstandards.gov.au/consumer/labelling/dates/Pages/default.aspx
Poor storing conditions and handling can affect both use by and best before dates, making the food have shorter shelf life. An example is leaving refrigerated foods out of the fridge for extended periods during it’s use causing the food’s temperature to increase, accelerating bacterial growth.
